I have a block house built in 1947, it's covered in stucco. Anyway, I'm considering adding siding but have some questions. I've read a few threads here about siding over block but I'm curious about removing the stucco first, seems everyone else has bare blocks. Some spots are very light to where I can see the outline of the blocks (and don't see a wire mesh I've read about) and other spots are very thick with stucco. I don't think I should just side or fur over the stucco because it's so uneven and don't want the siding to be wavy. Is it okay to remove strips of stucco just to make room for furring strips or is there a reason all stucco should be removed? Also, when I anchor the furring strips does it matter if I anchor into the mortar or if I anchor into the block? Does it depend on what kind of block I have or is mortar always better for anchoring? What is the best way to remove stucco? I have an air compressor with an air chisel but sometimes the old school hammer works better than these fancy tools. Are there special chisels for this or do I just use a pry bar? Feel free to add any additional advice, I'm usually handy but working with stucco and block is pretty new to me.

Don't try to remove the stucco. It would be massively time consuming. Instead, install furring strips with concrete screws. After the furring strips are in place pull a tight string horizontally from end to end at intervals. Loosen the concrete screw then use cedar shims to adjust the furring strip to the string. If you keep it within 1/4" or so you should be fine. You can also let the siding "float" across a furring strip and not fasten it down completely. This is especially true with vinyl siding, although you don't mention what type of siding you're going to use.
hth, Doug